Example usage for java.util Random nextDouble

Introduction

In this page you can find the example usage for java.util Random nextDouble.

Prototype

public double nextDouble()

Source Link

Document

Returns the next pseudorandom, uniformly distributed double value between 0.0 and 1.0 from this random number generator's sequence.

Usage

From source file:nova.core.util.math.Vector2DUtil.java

/**
 * @return Creates a random unit vector//  www  . ja va  2 s .co  m
 */
public static Vector2D random() {
    Random random = new Random();
    return new Vector2D(random.nextDouble(), random.nextDouble()).scalarMultiply(2).subtract(ONE);
}

From source file:util.PositionHelper.java

/**
 * Creates a latitude in portugal// w  w  w  .  jav  a2  s .co  m
 *
 * @return a latitude as double
 */
public static Double createLatitude() {
    Random r = new Random();
    Double latitude = (r.nextDouble() * -360.0) + 180.0;
    boolean latidudeBool = true;
    while (latidudeBool) {
        if (latitude < Constants.NORTH_BORDER && latitude > Constants.SOUTH_BORDER) {
            latidudeBool = false;
        } else {
            latitude = (r.nextDouble() * -360.0) + 180.0;
        }
    }
    return latitude;
}

From source file:util.PositionHelper.java

/**
 * Creates a longitude in portugal//  w  w w . j  a  va 2s.  c  o m
 *
 * @return a longitude as double
 */
public static Double createLongitude() {
    Random r = new Random();
    Double longitude = (r.nextDouble() * -180.0) + 90;
    boolean longitudeBool = true;
    while (longitudeBool) {
        if (longitude < Constants.EAST_BORDER && longitude > Constants.WEST_BORDER) {
            longitudeBool = false;
        } else {
            longitude = (r.nextDouble() * -180.0) + 90;
        }
    }
    return longitude;
}

From source file:edu.berkeley.sparrow.examples.ProtoFrontendAsync.java

public static double generateInterarrivalDelay(Random r, double lambda) {
    double u = r.nextDouble();
    return -Math.log(u) / lambda;
}

From source file:nova.core.util.math.Vector3DUtil.java

/**
 * @return Creates a random unit vector/*from  w  w w .j a v  a  2s.  c  om*/
 */
public static Vector3D random() {
    Random random = new Random();
    return new Vector3D(random.nextDouble(), random.nextDouble(), random.nextDouble()).scalarMultiply(2)
            .subtract(ONE);
}

From source file:com.caseystella.analytics.distribution.RotationTest.java

public static DataPoint nextDataPoint(Random r, long ts, long delta, List<DataPoint> points) {
    double val = r.nextDouble() * 1000;
    DataPoint dp = (new DataPoint(ts, val, null, "foo"));
    if (points != null) {
        points.add(dp);//from w  w w .j  ava 2  s. c om
    }
    ts += delta;
    return dp;
}

From source file:rsa_matrices.Helpers.java

public static double[][] generateMatrix(int rows, int columns) {
    double result[][];
    result = new double[rows][columns];
    for (int row = 0; row < rows; row++) {
        for (int col = 0; col < columns; col++) {
            Random random = new Random();
            result[row][col] = 2 * random.nextDouble();
        }//from  w w w  . j  av  a2s . co m
    }
    return result;
}

From source file:com.insightml.math.distributions.DiscreteDistribution.java

public static int sample(final double[] discreteDistribution, final Random random) {
    final double rand = random.nextDouble();
    double sum = 0;
    for (int i = 0; i < discreteDistribution.length; ++i) {
        sum += discreteDistribution[i];/*from  w  ww  .ja va2 s .  c o  m*/
        if (rand <= sum) {
            return i;
        }
    }
    throw new IllegalStateException(rand + " / " + sum);
}

From source file:org.ensor.fftmusings.rnn.GravesLSTMCharModellingExample.java

/**
 * Given a probability distribution over discrete classes, sample from the
 * distribution and return the generated class index.
 *
 * @param distribution Probability distribution over classes. Must sum to
 * 1.0/*from  w  w w.j  a v a 2  s . c o  m*/
 */
private static int sampleFromDistribution(double[] distribution, Random rng) {
    double d = rng.nextDouble();

    double sum = 0.0;
    for (int i = 0; i < distribution.length; i++) {
        sum += distribution[i];
        if (d <= sum) {
            return i;
        }
    }
    //Should never happen if distribution is a valid probability distribution
    throw new IllegalArgumentException("Distribution is invalid? d=" + d + ", sum=" + sum);
}

From source file:com.oculusinfo.ml.spark.unsupervised.TestDPMeans.java

public static void genTestData(int k) {
    PrintWriter writer;/*from  www.jav  a 2s  . co m*/
    try {
        writer = new PrintWriter("test.txt", "UTF-8");

        // each class size is equal 
        int classSize = 1000000 / k;

        double stdDev = 30.0;

        // generate k classes of data points using a normal distribution with random means and fixed std deviation
        for (int i = 0; i < k; i++) {
            Random rnd = new Random();

            double meanLat = rnd.nextDouble() * 400.0;
            double meanLon = rnd.nextDouble() * 400.0;

            // randomly generate a dataset of lat, lon points
            for (int j = 0; j < classSize; j++) {
                double x = rnd.nextGaussian() * stdDev + meanLat;
                double y = rnd.nextGaussian() * stdDev + meanLon;

                writer.println(x + "," + y);
            }
        }
        writer.close();
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (UnsupportedEncodingException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}